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Li Y, Bagheri P, Chang P, Zeng A, Hao J, Fung A, Wu JY, Shi L. Direct Imaging of Lipid Metabolic Changes in Drosophila Ovary During Aging Using DO-SRS Microscopy. FRONTIERS IN AGING 2022; 2:819903. [PMID: 35822015 PMCID: PMC9261447 DOI: 10.3389/fragi.2021.819903] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 12/29/2021] [Indexed: 01/09/2023]
Abstract
Emerging studies have shown that lipids and proteins play versatile roles in various aspects of aging. High-resolution in situ optical imaging provides a powerful approach to study the metabolic dynamics of lipids and proteins during aging. Here, we integrated D2O probing and stimulated Raman scattering (DO-SRS) microscopy to directly visualize metabolic changes in aging Drosophila ovary. The subcellular spatial distribution of de novo protein synthesis and lipogenesis in ovary was quantitatively imaged and examined. Our Raman spectra showed that early stages follicles were protein-enriched whereas mature eggs were lipid-enriched. DO-SRS imaging showed a higher protein synthesis in the earlier developing stages and an increased lipid turned over at the late stage. Aged (35 days) flies exhibited a dramatic decrease in metabolic turnover activities of both proteins and lipids, particularly, in the germ stem cell niche of germarium. We found an accumulation of unsaturated lipids in the nurse cells and oocytes in old flies, suggesting that unsaturated lipids may play an important role in the processes of oocyte maturation. We further detected changes in mitochondrial morphology and accumulation of Cytochrome c during aging. To our knowledge, this is the first study that directly visualizes spatiotemporal changes in lipid and protein metabolism in Drosophila ovary during development and aging processes. Our study not only demonstrates the application of a new imaging platform in visualizing metabolic dynamics of lipids and proteins in situ but also unravels how the metabolic activity and lipid distribution change in Drosophila ovary during aging.
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Affiliation(s)
- Yajuan Li
- The Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Pegah Bagheri
- The Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Phyllis Chang
- The Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Audrey Zeng
- The Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Jie Hao
- The Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Anthony Fung
- The Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Jane Y. Wu
- Department of Neurology, Northwestern University, Chicago, IL, United States
| | - Lingyan Shi
- The Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
- *Correspondence: Lingyan Shi,
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Tiwari SK, Mandal S. Mitochondrial Control of Stem Cell State and Fate: Lessons From Drosophila. Front Cell Dev Biol 2021; 9:606639. [PMID: 34012959 PMCID: PMC8128071 DOI: 10.3389/fcell.2021.606639] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 04/06/2021] [Indexed: 01/09/2023] Open
Abstract
Over the years, Drosophila has served as a wonderful genetically tractable model system to unravel various facets of tissue-resident stem cells in their microenvironment. Studies in different stem and progenitor cell types of Drosophila have led to the discovery of cell-intrinsic and extrinsic factors crucial for stem cell state and fate. Though initially touted as the ATP generating machines for carrying various cellular processes, it is now increasingly becoming clear that mitochondrial processes alone can override the cellular program of stem cells. The last few years have witnessed a surge in our understanding of mitochondria's contribution to governing different stem cell properties in their subtissular niches in Drosophila. Through this review, we intend to sum up and highlight the outcome of these in vivo studies that implicate mitochondria as a central regulator of stem cell fate decisions; to find the commonalities and uniqueness associated with these regulatory mechanisms.
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Affiliation(s)
- Satish Kumar Tiwari
- Developmental Genetics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Sudip Mandal
- Molecular Cell and Developmental Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
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Zhang Y, Wang ZH, Liu Y, Chen Y, Sun N, Gucek M, Zhang F, Xu H. PINK1 Inhibits Local Protein Synthesis to Limit Transmission of Deleterious Mitochondrial DNA Mutations. Mol Cell 2019; 73:1127-1137.e5. [PMID: 30772175 DOI: 10.1016/j.molcel.2019.01.013] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 11/05/2018] [Accepted: 01/09/2019] [Indexed: 12/22/2022]
Abstract
We have previously proposed that selective inheritance, the limited transmission of damaging mtDNA mutations from mother to offspring, is based on replication competition in Drosophila melanogaster. This model, which stems from our observation that wild-type mitochondria propagate much more vigorously in the fly ovary than mitochondria carrying fitness-impairing mutations, implies that germ cells recognize the fitness of individual mitochondria and selectively boost the propagation of healthy ones. Here, we demonstrate that the protein kinase PINK1 preferentially accumulates on mitochondria enriched for a deleterious mtDNA mutation. PINK1 phosphorylates Larp to inhibit protein synthesis on the mitochondrial outer membrane. Impaired local translation on defective mitochondria in turn limits the replication of their mtDNA and hence the transmission of deleterious mutations to the offspring. Our work confirms that selective inheritance occurs at the organelle level during Drosophila oogenesis and provides molecular entry points to test this model in other systems.
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Affiliation(s)
- Yi Zhang
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Zong-Heng Wang
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Yi Liu
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Yong Chen
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Nuo Sun
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Marjan Gucek
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Fan Zhang
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Hong Xu
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA.
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